1. Field of the Invention
The present invention relates to a mobile terminal apparatus, and more particularly to a mobile phone comprising an upper housing and a lower housing in which the upper housing is configured to be slidably and rotatably mounted on the lower housing.
2. Description of the Related Art
Conventionally, a straight type or a flip type is very popular as a shape of a conventional mobile phone. Recently, another type has appeared, wherein an upper housing is placed on a lower housing, a display provided on a main surface of the upper housing is always exposed outside, the upper housing is configured to slidably rotate by 180 degrees via a hinge to expose a key input portion provided on the lower housing (a so-called 180-degree open style) such as disclosed in Japanese Laid-Open Patent No. 2002-135380.
Among slide-rotation type mobile terminal apparatuses (hereinafter simply called a mobile terminal or a terminal), such type that, while holding one of housings with one hand, is able to rotate the other housing both in a clockwise direction and a counterclockwise direction, has advantages in satisfying both right-handed and left-handed users, or user preferences.
However, in a conventional slide-rotation type mobile terminal apparatus, positioning of the lower housing relative to the upper housing when both housings are closed and holding them to the position were relied upon a mechanism and precision of a hinge portion. Therefore, among others, the type in which the upper housing is able to rotate both in a clockwise direction and in a counterclockwise direction, has a low positioning precision because of a piece-to-piece variation of hinges, and the possibility that the position of the upper housing tends to be displaced or tilted relative to the lower housing in the closed state. In order to avoid this inconvenience, if the mechanism of the hinge portion is made complicated, there arises the problem of causing a cost increase.
The present invention has been made in the above-described background and an aspect of the invention is to provide a mobile terminal apparatus of a slide-rotation type having a novel structure capable of realizing a proper positioning and holding of both upper and lower housings with a relatively simple structure.